What is the input terminal impedance at the center if a folded dipole antenna?
A. 300 ohms
B. 72 ohms
C. 50 ohms
D. 450 ohms

1 Answer

Answer :

A. 300 ohms

Related questions

Description : The input terminal impedance at the center of a folded dipole antenna is A. 72 Ω B. 300 Ω C. 50 Ω D. 73 Ω

Last Answer : B. 300 Ω

Description : Which antenna is not a wideband? A. Discone B. Folded dipole C. Helical D. Marconi

Last Answer : D. Marconi

Description : Which is a non-resonant antenna? A. Rhombic antenna B. Folded dipole C. End-fire array D. Yagi-Uda antenna

Last Answer : A. Rhombic antenna

Description : Which is the non-resonant antenna? A. Broadside Antenna B. Folded Dipole C. Rhombic antenna D. End fire array

Last Answer : C. Rhombic antenna

Description : What is the end impedance of a half-wave dipole? A. 73 Ω B. 72 Ω C. 250 Ω D. 2500 Ω

Last Answer : D. 2500 Ω

Description : A final amplifier of a radio transmitter draws 250 mA of plate current when the plate supply voltage is 1400 volts. If the plate circuit efficiency is 80% and the transmitter is connected to an antenna having a feed impedance of 70 ohms, ... at the feed-point? A. 4.0 A B. 2.2 A C. 1.25 A D. 2.0 A

Last Answer : D. 2.0 A

Description : In horizontal-dipole antenna, the polarization is A. in the vertical direction B. in the horizontal direction C. circular D. measured at the center of the antenna

Last Answer : B. in the horizontal direction

Description : Known as the technique for adding a series inductor at or near the center of an antenna element in order to cancel the capacitive reactance of an antenna. A. Dipole B. Center loading C. Reflector D. loading coil

Last Answer : D. loading coil

Description : Where do the maximum current and minimum voltage values on a resonant Hertz dipole exist? A. Center of the antenna B. Near the end of the antenna C. Near the center of the antenna D. Ends of the antenna

Last Answer : A. Center of the antenna

Description : A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW ... Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24

Last Answer : B. 2.6

Description : A dipole antenna requires to be feed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11 ... ( Gain referred to this particular dipole) A. 4.24 B. 1.81 C. 4.75 D. 2.6

Last Answer : D. 2.6

Description : Calculate the noise figure of the receiver whose RF amplifier has an input resistance of 1000Ω and an equivalent shot-noise resistance of 2000Ω, a gain of 25 and load resistance of 125 kΩ. Given that the bandwidth is 1. ... to an antenna with an impedance of 75Ω. A. 30.3 B. 3.03 C. 303 D. .303

Last Answer : A. 30.3

Description : What is the input impedance of a transmission line if its characteristic impedance is 300 Ω and the load is 600 Ω? Assume a quarter wavelength section only. A. 150 kΩ B. 150 mΩ C. 150 Ω D. 2 Ω

Last Answer : C. 150 Ω

Description : Which of the following is not common transmission line impedance? A. 50 ohms B. 120 ohms C. 75 ohms D. 650 ohms

Last Answer : B. 120 ohms

Description : Indicate the antenna thatisnotwideband: a. Discone b. Folded Dipole c. Helical d. Marconi

Last Answer : d. Marconi

Description : One ofthe followingconsistsof nonresonant antennas: a.The rhombic antenna b. The folded dipole c. The end-fire array d. The broadside array

Last Answer : a.The rhombic antenna

Description : Draw the radiation pattern for Dipole antenna: (i) Half wave dipole (ii) Folded dipole.

Last Answer : The radiation pattern for Half wave dipole antenna The radiation pattern for Folded dipole antenna.

Description : ECE Board Exam March 1996 A receiver connected to an antenna whose resistance is 50 ohms has an equivalent noise resistance of 30 ohms. What is the receiver’s noise temperature? A. 754 K B. 464 K C. 174 K D. 293 K

Last Answer : C. 174 K

Description : What is the characteristic impedance of a single wire with a diameter d= 0.25 mm placed at the center between grounded parallel planes separated by 1 mm apart. The wire is held by a material with a velocity factor of 0.75. A. 85 Ω B. 63 Ω C. 50 Ω D. 75 Ω

Last Answer : D. 75 Ω

Description : What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain? A. 300 W B. 315 W C. 31.5 W D. 69.9 W

Last Answer : C. 31.5 W

Description : Which antenna is not grounded at one end? A. Hertz B. Marconi C. Dipole D. Whip

Last Answer : C. Dipole

Description : The effect of adding parasitic elements of a Hertz dipole is to A. make the antenna more omnidirectional B. reduce its resonant frequency C. increase the antenna’s power gain D. All of these

Last Answer : C. increase the antenna’s power gain

Description : What is the gain of an antenna over a half-wavelength dipole when it has 6 dB gain over an isotropic radiator? A. 6.0 dB B. 8.1 dB C. 3.9 dB D. 10.0 dB

Last Answer : C. 3.9 dB

Description : What antenna radiates equally in all directions? A. Vertical antenna B. isotropic antenna C. Horizontal antenna D. Dipole antenna

Last Answer : B. isotropic antenna

Description : In order to get maximum radiation to all surrounding points in the horizontal plane, the antenna used is a A. vertical loop B. vertical quarter-wavelength rod C. array which includes parasitic elements D. a horizontal Hertz dipole

Last Answer : B. vertical quarter-wavelength rod

Description : If the length of a Hertz dipole is decreased A. its resonant frequency will be lowered its distributed inductance will be increased B. its distributed inductance will be decreased C. its ... frequency will be increased D. its distributed capacitance between the antenna and ground will be increased.

Last Answer : C. its resonant frequency will be increased

Description : How is it possible to lower the resonant frequency of Hertz dipole antenna? A. By reducing the frequency at the transmitter B. By connecting a capacitor in series with the antenna C. By the connecting a resistor in series with the antenna D. By connecting an inductor in series with the antenna

Last Answer : D. By connecting an inductor in series with the antenna

Description : The frequency of operation of a dipole antenna cut to a length of 3.4 m. A. 88 MHz B. 44 MHz C. 22 MHz D. 11 MHz

Last Answer : B. 44 MHz

Description : An antenna which is one-tenth wavelength long A. Hertzian dipole B. Loop antenna C. Marconi antenna D. Elementary doublet

Last Answer : D. Elementary doublet

Description : An antenna with unity gain A. Rhombic B. Half-wave dipole C. Isotropic D. Whip

Last Answer : C. Isotropic

Description : What is the radiation characteristic of a dipole antenna? A. Omnidirectional B. Bidirectional C. Unidirectional D. Hemispherical

Last Answer : B. Bidirectional

Description : Which antenna is a properly terminated? A. Marconi B. Rhombic C. Dipole D. Yagi-Uda

Last Answer : B. Rhombic

Description : What is the gain of the Hertzian dipole over isotropic antenna? A. 1.64 dB B. 2.15 dB C. 1.76 dB D. 1.55 dB

Last Answer : C. 1.76 dB

Description : What antenna can be used to minimize the effect of Faraday rotation of polarization? A. Dipole B. Parabolic C. Helical D. Rhombic

Last Answer : C. Helical

Description : Type of antenna which is normally used for satellite tracking service. A. Omni B. Helical C. Yagi D. Dipole

Last Answer : B. Helical

Description : Refers to a type of beam antenna which uses two or more straight elements arranged in line with each other. A. Dipole antenna B. Yagi antenna C. Whip antenna D. Rhombic antenna

Last Answer : B. Yagi antenna

Description : The product of the power supplied to the antenna and its gain relative to a half-wave dipole in a given direction. A. Peak envelope power B. ERP C. Rated power D. Carrier power’

Last Answer : B. ERP

Description : Unity gain antenna A. Isotropic B. Rhombic C. Half-wave dipole D. Dummy

Last Answer : A. Isotropic

Description : The frequency of operation of a dipole antenna cut to length of 3.4 m. A. 42.9 MHz B. 61.3 MHz C. 38.5 MHz D. 53.5 MHz

Last Answer : A. 42.9 MHz

Description : Which is properly terminated antenna? A. Rhombic B. Hertz C. Marconi D. Dipole

Last Answer : A. Rhombic

Description : A type of array antenna which consists of one half-wave driven dipole, one reflector and one director A. Hertzian dipole B. Yagi-uda C. Broadside collinear D. Log periodic dipole array

Last Answer : B. Yagi-uda

Description : ECE Board Exam March 1996 The standard reference antenna for the directive gain is ___________. A. elementary doublet B. isotropic antenna C. half-wave dipole D. infinitesimal dipole

Last Answer : B. isotropic antenna

Description : What is the impedance in ohms of a transformer marked for 25V, 4W, when the secondary is correctly loaded? A. 150 Ω B. 156 Ω C. 160 Ω D. 165 Ω

Last Answer : B. 156 Ω

Description : Three audio waves with 100,200 and 300 volts amplitude respectively, simultaneously modulate a 450 volts carrier. What is the total percent of modulation of the AM wave? A. 69 % B. 115.5 % C. 50% D. 83%

Last Answer : D. 83%

Description : The ratio of the monthly salaries of A and B is in the ratio 15 : 16 and that of B and C is in the ratio 17 : 18. Find the monthly income of C if the total of their monthly salary is Rs 1,87,450. A) Rs 66,240 B) Rs 72,100 C) Rs 62,200 D) Rs 65,800 E) Rs 60,300

Last Answer : Answer: A A/B = 15/16 and B/C = 17*18 So A : B : C = 15*17 : 16*17 : 16*18 = 255 : 272 : 288 So C’s salary = [288/(255+272+288)] * 1,87,450= Rs 66,240

Description : Not a reason for the use of an antenna coupler. A. To make the antenna look resistive B. To provide the output amplifier with the correct load impedance C. To discriminate against harmonics D. To prevent re-radiation of the local oscillator

Last Answer : D. To prevent re-radiation of the local oscillator

Description : A shunt-fed quarter-wavelength Marconi antenna A. has maximum RF impedance to ground at its feedpoint B. has a current null at its feedpoint C. has a zero DC resistance to ground D. has zero RF resistance to ground

Last Answer : C. has a zero DC resistance to ground

Description : What is included in the total resistance of an antenna system? A. Radiation resistance plus space impedance B. Radiation resistance plus transmission resistance C. Transmission line resistance plus radiation resistance D. Radiation resistance plus ohmic resistance

Last Answer : D. Radiation resistance plus ohmic resistance

Description : What is meant by the term radiation resistance for an antenna? A. The resistance in the trap coils to received signal B. An equivalent resistance that would dissipate the same amount of power as ... antenna C. The specific impedance of the antenna D. Losses in the antenna elements and feed line

Last Answer : B. An equivalent resistance that would dissipate the same amount of power as that radiated from an antenna

Description : A convenient method of determining antenna impedance. A. Stub matching B. Reactance circle C. Smith chart D. Trial and error

Last Answer : C. Smith chart